A martial class on its own does not increase chances, only the features/abilities of the class do.

  • For example Fighters/Rangers both have Fighting Style (Archery) which increases ranged accuracy by 10%.
  • Fighters (Battle Masters) have Feinting/Precision Attack(s) to increase accuracy.
  • Bard and Paladin for example do not have any features that increase accuracy.

So a class on its own doesn't, but its features do (if obtained).